1. Field of the Art
The present invention relates to a shutter opening and closing mechanism for cameras.
2. Prior Art
A plurality of divided shutter blades are operated usually by a shutter operating member to move sequentially through different angles, respectively, thereby opening and closing the aperture. With a focal-plane shutter, an area required to cover the aperture is relatively large and the divided shutter blades tend to become increased in size, thereby necessitating a large space for accommodating the shutter blades therein. Thus, it is difficult to utilize the divided shutter blades in small size cameras. The size of the divided shutter blades also governs the overall size of a single lens reflex camera which finds wide use in recent years, because the shutter blades charged beneath the view finder mounted on top of the camera body travel downwardly of the shutter aperture to effect exposure operation. The spatial limitation makes a shutter with the vertically movable divided blades more disadvantageous than a conventional focal-plane shutter having a horizontally movable curtain. One proposal to reduce the size of the shutter having the divided blades would be to subdivide the blades; however, as the blades are subdivided, the light-interrupting characteristic becomes reduced, thus imposing a limitation on effective subdivision.